hey guys, pretty stumped here. i have a 98 y8 turbo and when i rev hard or hit boost (9psi) my temp gauage rises and as soon as i let off it drops down. i have arp headstuds no sign of headgasket issue from what i see....any ideas?

 

Water pump is the first thing that pops into my head.

 

hmmm didnt think of that. but im not losing antifreeze

 

Not losing antifreeze has nothing to do with how your water pump performs. It could be weak or near failure point. Have you checked all your hoses and your thermostat?

 

hoses seem alright thermostat does open and close when i test it in water. wouldnt u see antifreeze come out of the weep hole if water pump was bad?

 

When does it do this when you are sitting still or moving or both also are you running a air to water charged are cooler?

 

it does it while driving. when i really get on it.

 

anyone? come on someones gotta know something

 

How old is your radiator? Is it stock, performance, or ebay knockoff "performance" (which is often worse than stock)?

Really sounds like the main problem is a restriction in the radiator, or problems with the air side (missing fins, blocked airflow) that it can't get rid of heat.

 

its a stock rad.12 years old. i just flushed it, bought a new thermostat, and upper rad house. still does it. i can sit and just rev the motor and them temp will rise then drop. so im really lost